Electronic access control systems typically provide the means to exchange access control information between electronic devices. By way of example, an electronic key or other electronic access control device may transmit, via wired or wireless communication technologies, authentication information such as an access code to an electronic lock in order to initiate an unlocking event.
In many access control systems, existing communication techniques suffer from disadvantages that may make the exchange of desired information impractical. For instance, if the time period required to transmit or exchange access control information is perceptible to users, it can substantially reduce the utility of the system. In a facility where instantaneous access to an area or item is desired, time delays associated with electronic communications or configuration of devices for communication may be intolerable. Moreover, it has become commonplace in the broad field of electronic access control to energize devices with replaceable or rechargeable power sources, such as batteries. Frequent exchange of information between devices can quickly drain the capacity of depletable power sources, rendering the system inoperative.